Dr. Carballo Rubio is an expert on the implications that quantum gravity may have for our understanding of the structure astrophysical black holes. He has studied in detail whether some of these implications can lead to noticeable effects detectable with current or near-future electromagnetic and gravitational wave observatories. Aside from this main line of research, he has studied other phenomenological aspects of quantum gravity such as possible modifications to the famous Unruh effect, as well as devoted time to studying modified gravity theories and other open issues such as the cosmological constant problem or the emergence of gravity in diverse scenarios.